Flange clamp for an insulating weatherproof enclosure

ABSTRACT

A flange clamp having a C-shaped configuration, the opening between the ends of the clamp being slightly smaller than the diameter of the envelope to be clamped. The construction is such that the clamp is snap-engaged on the envelope to provide a security link to the envelope that it is associated with. The clamp is also provided with compression limiters so that only a predetermined compression force will be applied to the envelope flange.

O United States Patent 11 1 1111 3,913,959 Larkin 1 Oct. 21, 1975 [5 FLANGE CLAMP FOR AN INSULATING 1,593,041 7/1926 Stewart 292/2S6.67 x

WEATHERPROOF ENCLOSURE [75] Inventor: Oscar L. Larkin, Jackson, Miss. rim ry a i er-Richa d Moore [73] Assignee: Allis-Chalmers Corporation, Attorney Agent or Firm-Robert Jones Milwaukee, Wis. [22] Filed: May 28, 1974 ABSTRACT [2|] Appl. No.: 473,810 A flange clamp having a C-shaped configuration, the opening between the ends of the clamp being slightly smaller than the diameter of the envelope to be clamped. The construction is such that the clamp is [58] dd of 67 256 6 snap-engaged on the envelope to provtde a secunty 292/256 i link to the envelope that it is associated with. The clamp is also provided with compression limiters so [56] Reterences Cited that only a predetermined compression force will be applied to the envelope flange.

3 Claims, 2 Drawing Figures US. Patent Oct. 21, 1975 Sheet 10f2 3,913,959

U.S. Patent Oct. 21, 1975 Sheet 2 of2 3,913,959

FLANGE CLAMP FOR AN INSULATING WEATHERPROOF ENCLOSURE BACKGROUND OF THE INVENTION It is desirable in mounting insulating weatherproof enclosures or envelopes on supporting structure to effect a rigid connection between the envelope and the supporting structure. The arrangement must provide a mechanical connection which is strong enough to retain the envelope in position against the action of high wind loads, ice, snow and the like. However, the holddown arrangement cannot place a stress on the portion of the envelope to which it is engaged.

In conventional securing arrangements bolts are generally used in conjunction with some type of resilient bearing component for reducing the compression forces on localized areas of the envelope flange. While this type of an arrangement is functional, it has many disadvantages. For example, in tightening the holddown bolts only a limited amount of force can be applied and this usually requires the use of a torque wrench which may not be readily available when required. Also, employing bolts with the necessary associated individual resilient bearing retainers make it extremely difficult for a single operator to install. Another drawback in using bolts with associated individual retainers is the strong possibility of misplacing or dropping one of the parts in a highly critical component unit such as a tank or in an operating mechanism.

SUMMARY OF THE INVENTION extend through suitable flange openings to engage on the supporting structure.

Accordingly, it is a general object of the invention to provide a novel clamping arrangement which applies an equalized compression force on the entire flange of an insulator envelope.

Still another object of the invention is to provide a clamp arrangement for a circular member which cannot be inadvertently dislodged.

Yet another object of the invention is to provide a clamp arrangement comprising a pair of identical C- shaped configured members arranged adapted to be interacting and which operate together as a closed clamping system.

Another object of the invention is to provide a clamping arrangement having compression force limiting means.

Further objects and advantages of the invention will become more readily apparent from the specification taken in conjunction with the drawings.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary view of the bottom portion of an insulating weatherproof enclosure showing the clamping arrangement in operative position;

FIG. 2 is a view in horizontal section taken in a plane represented by the line 11-" in FIG. 1 showing both of the C-shaped clamp rings in position on the envelope and a ring as it would appear just prior to its being engaged on the periphery of the envelope shown in phantom lines;

FIG. 3 is a plan view of the two identical C-shaped clamp members disposed in relation to one another for assembly on the envelope; and

FIG. 4 is a view in vertical section through one of the C-shaped clamp members taken in a plane represented by the line IV-IV in FIG. 3.

DESCRIPTION OF THE INVENTION Referring to the drawings, the numeral 10 designates an electrical device such as a high voltage vacuum interrupter or vacuum switch. The particular illustrated device includes an elongated insulating weatherproof cylindrical envelope 12 that is provided with an axial bore 14 and a plurality of external axially spaced peripheral skirts 16, one of which is shown. The lower portion of the envelope 12 is formed with a radial outwardly extending flange portion, generally indicated at 17, which serves as a base for mounting the envelope 12 on a supporting structure 18. The radial flange 17 is formed with a plurality of notches or recesses 19. Associated with each notch 19 is a recess 21 which is located directly above the notch 19. The depth of each recess 21 is deeper than the associated notch 19 with the resulting wall surface 23 being formed with a radius. The edges or ends 26 and 27 of wall surfaces 23 adjacent the exterior surface of the envelope 12 are formed as radii to present a smooth contour surface. The recesses 21 serve to accommodate the nuts 28 of hold-down bolts 29, as clearly shown in FIG. 1.

As is well known, insulating envelopes such as the envelope 12 are usually extremely susceptible to being damaged when subjected to compression forces. This is especially true in locations such as at the flange and at the area of bolt holes. Thus, it is extremely difficult to bolt the envelope to a supporting structure.

As hereinafter described, a novel and improved clamp has been conceived which provides a rigid and strong means for securing an insulating envelope to a supporting structure. The clamp means not only secures the envelope to the supporting structure but also prevents an excess compression force from being applied to the envelope flange. In addition, the improve clamp means operates in a manner to lock on to the envelope so as to eliminate the possibility of inadvertent loss when the envelope is erected in position in the field. Further, with the arrangement disclosed, field assembly is facilitated in that one service person is all that is required to secure the electrical device in place.

As shown in FIGS. 2, 3 and 4, the clamp means 35 comprises two identical members 36 and 36A. Since the members 36 and 36A are identical, a description of the member 36 will be given and such description will apply to the member 36A with like parts being identitied with the same identifying reference number followed by a suffix letter A.

The member 36 is in the form of an open ended partial ring having a C-shaped configuration. The dimension X between the ends 37 and 38 of the member 36 is slightly less than the diameter of the envelope 12 measured at the area just above the recesses 23. As best shown in FIG. 2, the clamp member 36 is provided with three bolt openings 41, 42 and 43 to receive individual bolts 29 which are arranged so that the bolt holes 41 and 43 are diametrically opposite each other. The bolt hole 42 is located at a point equidistant from the bolt holes 41 and 43. The axes of the bolt holes 41, 42 and 43 are on diameters which are perpendicular to each other. As viewed in FIG. 3, the bottom surface 46 at the end 37 of the clamp member 36 is relieved as at 47. This relieved portion 47 extends along the clamp memher to a line which is located at a distance from the axis of the bolt hole 43 that is substantially equal to the distance from the end 37 to the axis of the bolt hole 43. The top surface 51 of the end 38 which is opposite to the surface 47 is also relieved. The relieved surface 51 has an arcuate length slightly greater than the length of the relieved surface 47. The clamp member 36 is constructed such that the length of the center of bolt hole 43 to the clamp end 37 is substantially equal to the distance from the center of bolt hole 41 to the end of relieved surface 51 at end 60, but is slightly less than the distance from the center of bolt hole 43 to the end of the relieved surface 47 at end 61 or from the center of bolt hole 43A to the end of the relieved surface 47A at end 61A. The opposite clamp member 36A is substantially identical to clamp member 36.

Radius corners 72 and 73 are imparted from surface 47 to end 61 and from relieved surface 51 to ends 60 and 38 and from relieved surface 51A to ends 60A and 38A. The inside radius corners 74 and 75 of surface 51A to end 60A and surface 51 to end 60 prevent stress concentrations which could cause fracture of the flange clamp during the bolting operation. The outside radius corners enable end 37 to be abutted to end 60A and end 37A to be abutted to end 60 with the radius corners nesting within one another. Thus, when the two clamp members 36 and 36A are joined in clamping engagement about the periphery of the envelope 12 the relieved surface 47 of the clamp member 36 mates with the relieved surface 51A of the end 38A of the clamp member 36A. In like manner the relieved surface 51 of the end 38 of the clamp member 36 mates with the relieved surface 47A of the end 37A of the clamp member 36A. in mated engagement the two clamp members 36 and 36A form a circular clamp that engages the flange surface so as to exercise a clamping action on the entire flange rather than at localized points.

As previously mentioned, the compression force that is to be applied to the flange 17 must be limited. To this end, the clamp members 36 and 36A are provided with compression limiters which effectively and positively limit the amount of compression force that can be applied by the plurality of bolts 29. The compression limiters comprise a plurality of depending lugs such as the lugs 56 and 57 associated with the clamp member 36 and the similar lugs 56A and 57A associated with the clamp member 36A. The lugs 56 and 57 associate with the clamp member 36 are disposed at the bolt holes 41 and 42, respectively. The inner surfaces of the lugs are relieved to provide clearance for the passage of the bolts 29 as they extend through suitable openings in the supporting structure 18 and through the respective members 36 and 36A will firmly engage the adjacent surface 59 of the envelope flange 17. Since the flange surface 59 slopes radially outwardly, the surfaces 46 and 46A which engage the surface 59 are provided with a surface that complements the slope of the flange surface 59.

aligned bolt holes 41 and 41A, 42 and 42A and 43 and 43A. The length of the lugs 56 and 57 are ofa predetermined length and are sufficiently long enough so that the under or bottom surfaces 46 and 46A of the clamp As depicted in FIG. 1, the bottom surface of the envelope 12 adjacent to the supporting structure 18 abuts on a resilient sealing ring 71. The ring serves to seal the joint between the envelope 12 and the structure 18 to prevent water or other contaminants from seeping or percolating into the bore of the envelope 12. If it is contemplated that a sealing ring such as the ring 71 will be utilized, the length of the lugs 56 and 57 will, of course, reflect such increase in dimension and will be correspondingly lengthened.

in assembling the clamp members 36 and 36A in operative position on the envelope 12, the clamp member 36, which will exemplify the procedure for both members, is approached to the envelope at the area above the flange l7 and below the bottom shed 16. One end of the clamp member 36, such as the end 38, is entered into a recess 23 while the opposite end 37 engages the periphery of the envelope 12, as exemplified by the phantom lined position of the clamp member 36 in FIG. 2. With the clamp member 36 thus positioned, the end 38 will be disposed in the recess 23 while the end 37 will engage the periphery of the envelope 12. The clamp member is then given a light tap with the hand or with a soft mallet at the midpoint area of the member. This will cause the ends 37 and 38 of the clamp member 36 to spread slightly allowing the end 37 to move into the adjacent recess 23. With both of the ends 37 and 38 in diametrically opposite recesses 23, another slight tap will snap the clamp member into position around the periphery of the envelope 12 with both ends 37 and 38 located past a diameter line of the envelope. The same technique is used for locating the other clamp member 36A in position on the envelope. The

snap engagement of the clamp members 36 and 36A on the envelope provide an effective locking arrangement to maintain the clamp members on the envelope in a loose condition so as to prevent inadvertent loss of the members.

With the clamp members 36 and 36A disposed on the envelope 12 as described, the ends 37 and 38A and 37A and 38 are interengaged and the bolts 29 inserted through the openings in the support structure and through the aligned openings 41, 42, 43, 41A, 42A and 43A and the nuts engaged on the ends of the bolts. The nuts 28 are tightened and since the compression limiters S6, 57, 56A and 57A limited the amount of compression force that the clamp members can apply to the envelope flange, no particular force measuring device need be employed.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. ln clamping apparatus for securing an electrical device to a supporting device;

an insulating weatherproof cylindrical envelope adapted to be mounted on the supporting structure;

a radially outwardly extending flange formed integrally with said envelope in position thereon to be disposed adjacent to the supporting structure on which said envelope is mounted, said flange being constructed to present a sloping top surface which slopes downwardly and outwardly from the cylindrical body of said envelope;

the diameter of said cylindrical envelope; whereby by placing one end of a C-shaped clamp member in a recess the clamp member may be a pair of identical C-shaped clamping members cooperatively arranged on said flange of said envelope 5 in facing relationship;

each of said C-shaped clamping members being constructed with a sloping undersurface complementary to the sloping top surface of said flange, each of said C-shaped clamping members also having their end portions relieved in a manner that one end portion of each C-shaped member has the undersurface relieved, the arrangement being such that the relieved adjacent end portions of said C- at least three bolt-receiving openings formed in each of said C-shaped clamp members, two of said bolt openings being located one at each of the ends of the C-shaped clamp member with the axes of said shaped clamping member mate to provide an inter- 5 two bolt openlngs being disposed on a line which fggg gt gag f ss i figg 2?: gi zspgi will coincide with a diameter line of said opening clamping members are arranged in operative posiwhen. said clamp i f m operalwe plasmon on on said flange; and on said envelope, said third bolt opening being loa plurality of bolt members operatively engaged in cated. 'f z from the other two of Sam bolt the supporting structure and connected to said C- openmgs' an Shaped clamping members, said plurality of be at least two compression llmlters associated with members being operable to effect the forceful eneach of a Cfsllaped clamp m P of Sand gagemem of said Oshaped clamping members with compression l miters being disposed ad acent to a said flange in a manner that said C-shaped clampbolt opemng and ofsald P f f ing members apply an equalized clamping force on f f and the Qther of Sam compress?" i the entire surface of said flange to effectively se- P f disposed -l to the l opeflmg which cure h envelope i posmon on the supporting is disposed between the bolt opemngs In the ends styuctum of said C-shaped clamp member;

2. A securing apparatus according to claim 1 wherein h y l l P P clamp members said envelope is provided with a plurality of equispaced operatlve Interlocking arrangement the recesses formed in the cylindrical peripheral wall surange of said envelope said compression limiters face immediately above said flange; and, will be adjacent to a bolt opening so that the force said C-shaped members are constructed and arof the securing bolts will be limited to a predeterranged in a manner that the opening between the mined force applying amount. ends of said C-shaped member is slightly less than 

1. In clamping apparatus for securing an electrical device to a supporting device; an insulating weatherproof cylindrical envelope adapted to be mounted on the supporting structure; a radially outwardly extending flange formed integrally with said envelope in position thereon to be disposed adjacent to the supporting structure on which said envelope is mounted, said flange being constructed to present a sloping top surface which slopes downwardly and outwardly from the cylindrical body of said envelope; a pair of identical C-shaped clamping members cooperatively arranged on said flange of said envelope in facing relationship; each of said C-shaped clamping members being constructed with a sloping undersurface complementary to the sloping top surface of said flange, each of said C-shaped clamping members also having their end portions relieved in a manner that one end portion of each C-shaped member has the undersurface relieved, the arrangement being such that the relieved adjacent end portions of said C-shaped clamping member mate to provide an interengagement between the adjacent ends of said C-shaped clamping members when said C-shaped clamping members are arranged in operative position on said flange; and, a plurality of bolt members operatively engaged in the supporting structure and connected to said C-shaped clamping members, said plurality of bolt members being operable to effect the forceful engagement of said C-shaped clamping members with said flange in a manner that said C-shaped clamping members apply an equalized clamping force on the entire surface of said flange to effectively secure the envelope in position on the supporting structure.
 2. A securing apparatus according to claim 1 wherein said envelope is provided with a plurality of equispaced recesses formed in the cylindrical peripheral wall surface immediately above said flange; and, said C-shaped members are constructed and arranged in a manner that the opening between the ends of said C-shaped member is slightly less than the diameter of said cylindRical envelope; whereby by placing one end of a C-shaped clamp member in a recess the clamp member may be snap-engaged on the cylindrical envelope.
 3. A securing apparatus according to claim 2 wherein said flange is provided with a plurality of notches extending inwardly from the peripheral edge of the flange to the cylindrical wall surface of said envelope, said notches each being disposed opposite to an associated recess; at least three bolt-receiving openings formed in each of said C-shaped clamp members, two of said bolt openings being located one at each of the ends of the C-shaped clamp member with the axes of said two bolt openings being disposed on a line which will coincide with a diameter line of said opening when said clamp member is in operative position on said envelope, said third bolt opening being located equidistant from the other two of said bolt openings; and, at least two compression limiters associated with each of said C-shaped clamp members, one of said compression limiters being disposed adjacent to a bolt opening in an end of said C-shaped clamp member and the other of said compression limiter being disposed adjacent to the bolt opening which is disposed between the bolt openings in the ends of said C-shaped clamp member; whereby with said pair of C-shaped clamp members in operative interlocking arrangement on the flange of said envelope said compression limiters will be adjacent to a bolt opening so that the force of the securing bolts will be limited to a predetermined force applying amount. 